Cover clamp for electrical apparatus



Fb. 9, 19 37. E. D. TREANOR 2,070,499

COVER CLAMP FOR ELECTRICAL APPARATUS Filed Aug. 31, 1935 Inventor-z Edward D. Tr'eanor;

His Attorney.

Patented Feb. 9, 1937 COVER CLAMP FOR ELECTRICAL APPA I v RATUS I Edward D. Treanor, Pittsfield, Mass., assignor to I:

General Electric Company, a corporation of 1 n New York Y 7 Application Aimee, 19.35, Serial Nb;- 38,766. sol ms. (Craze-'55) lVIy invention relates to cover clamps for electrical apparatus casing and is particularly applicable in connection with clamps for holding securely in position the covers of casings of such electrical apparatus as transformers which are immersed in insulating oil or other liquid. The cover of a casing for liquid immersed transformers or other similar electrical devices should be held securely and tightly in place during normal operation of the enclosed electrical apparatus in order to protect the apparatus from outside dirt and moisture, but it is desirable that any means used for this purpose be not only effective and reliable but also of such construction that the cover may be quickly and easily released and the casing opened for inspection or other purposes.

The general object of the invention is to provide an improved cover clamp having these 'desirable features.

The invention will be better understood from the following description taken in connection with the accompanying drawing, in which Fig. 1 is a view of the upper part of a transformer casing with its cover secured in normal closed position by cover clamps constructed in accordance with the invention; Figs. 2 and 3 are views similar to that shown in Fig. 1, but with the cover. clamps loosened and the cover held in raised position by the clamps; Fig. 4 is a View of a fragment of the transformer casing with the cover clamp partially loosened; and Fig. 5 is a View similar to that shown in Fig. 4, but with the cover clamp loosened and tipped away from the cover to permit the cover to be raised.

Like reference characters indicate similar parts in the difierent figures of the drawing.

The transformer casing III shown in the drawing has a cover I I fitting over the upper edge of the side wall of the casing.

As shown in the drawing, a pair of bushings I2 extend through the cover II to insulate the high voltage leads from the transformer. part of a side pocket for insulating bushings for the low voltage transformer leads is also shown.

The cover II is normally held tightly in closed position, as shown in Fig. 1, by cover clamps I3, two such clamps being shown, although a larger number may be provided, if it is desired, particularly for a cover of large size.

Each cover clamp I3 includes a lug I4 welded or otherwise secured to the outer face of the side wall of the casing I0 just below its upper edge. This lug I4 has parallel spaced sides I5, with the inner part of their lower edges cut away or notched for engagement by lifting cables, such The upper as are frequently used duringhandling for ship ment. The clamp I3 further includes a rod I 6 with its lower end secured by a pivotal connection I! between the sides I 5 of the lug I4. A wing nut I8 is threaded onto the upper or outer end 5 of the rod I6. A holding member I9 has a cylindrical body portion 20 which mayslide freely on the rod I6. An upward extension 2I from the body portion .29 of the holding member is bent over at its outer end to. fit over the edge of the 10 cover H of the casing II]. A helical spring 22 is providedon the rod I6 between the wing nut I8 and the body portion 2|] of the holding member I9.

With the cover II in closed position and the 15 holding member I9 held close to the outer edge of the cover, the cover may be secured in normally closed position by tightening the wing nuts I8 of the cover clamps so as to draw the curved or hooked shaped upper ends of the holding mem- 0 bers I9 tightly down onto the cover. There may be, in some cases, a tendency for the holding members to be pulled laterally away from the cover and slip off its edge. This is efiectively prevented by side flanges 23 on the holding mem- 25 her I9 arranged to engage in notches 24 in the upper edges of the sides I5 of the lugs I4. These flanges 23 and the outer side edges of the notches 24 are inclined slightly upwardly and outwardly with respect to the rod I6 so that as the holding 30 member I9 is forced down into holding position on the edge of the cover II, the holding member will at the same time be drawn in toward the cover and any disengagement of the holding member from the cover effectively prevented. Fig. 1 of the drawing shows the cover II of the transformer casing held securely in place by two clamps I3 with the side flanges 23 engaged in the notches 24 to prevent accidental disengagement of the clamps. Fig. 4 shows a cover clamp 40 partially loosened and its side flanges 23 disengaged from the notches 24. Fig. 5 shows a clamp I3 pulled laterally away from its cover II about its pivotal connection I! with the lug I 4 so that it is free of the cover and the cover may be easily raised.

Under normal operating conditions of the transformer, it is desirable that the clamps I3 hold the cover II securely in place to exclude outside dirt and moisture, but there is always a 50 possibility that excessive pressure may develop inside the casing IB due to a fault in the transformer such as a breakdown of insulation. If such pressure becomes so high as to be dangerous, the springs 22 will yield and allow the cover 55 II to open slightly so as to relieve the pressure and prevent an explosive rupture of the easing l0.

Many transformers are mounted high above the ground on poles or in other positions which are not very easily accessible. It is, however, often necessary that such transformers be inspected or repaired. As shown in Fig. 3, the cover II is pivotally connected at one edge to the side of the casing H] by a link 25. The wing nuts I8 have notches 26 in their upper edges. When the cover II is raised as shown in Figs. 2 and 3, the clamps I3 may be pulled in toward the casing with the notches 26 under the edge of the cover to engage it and hold the cover in raised position while the transformer is inspected or repaired. The outer edge of the cover II is formed with a flange which fits easily into thenotches 26 so that the clamps cannot slip out of place accidentally and allow the cover to drop.

The invention has been explained by describing and illustrating a particular embodiment thereof, but it will be apparentthat changes may be made without departing from the spirit of the invention and the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. The combination with an electrical app-aratus casing having a cover, of a lug secured to the side of the casing below its cover, a holding member for engaging the cover, and means pivoted to the lug for tightening the holding member onto the cover, the lug being formed with a notch, and the holding member having a flange arranged to engage in the notch of the lug when in tightened position to prevent lateral motion of the holding member away from the cover.

2. The combination with an electrical apparatus casing having a cover, of a lug with spaced sides secured to the side of the casing below its cover, a holding member for engaging the cover, and means pivoted to the lug between its sides for tightening the holding member onto the cover, the sides of the lug having notches in their upper edges, and the holding member having side flanges arranged to engage in the notches of the lug when in tightened position to prevent lateral motion of the holding member away from the cover.

3. The combination with an electrical apparatus casing having a cover, of a lug with spaced sides secured to the side of the casing below its cover, a holding member for engaging the cover, and means including a rod pivoted to the lug between its sides for tightening the holding member onto the cover, the sides of the lug having notches in their upper edges, and the holding member having side flanges inclined to the rod and arranged to engage in the notches of the lug when in tightened position to prevent lateral motion of the holding member away from the cover.

EDWARD D. TREANOR. 

